Over the past 15 years, lasers and intense pulsed light systems have been used to treat a wide array of dermatological skin conditions. Examples of such systems are the CoolGlide system manufactured by Altus, Inc. for the treatment of unwanted hair, the Quantum system, manufactured by Lumenis, Inc. for photo rejuvenation, and the VBeam system manufactured by Candela, Inc. for the treatment of vascular lesions. The light emitted by each of these systems is very intense and poses a hazard to both the operator and patient. Undesired or unexpected emission from these systems can cause blindness, skin damage (when cooling mechanisms are not properly applied prior to emission), and damage to furniture, clothing, or other unintended targets. The sale of each of these systems is restricted by the United States Food and Drug Administration (FDA), and the safety of treatments performed by these machines relies on a well-trained operator to determine if conditions are satisfactory for emission. However, even in the hands of a well-trained operator, the safe use of these types of systems would be enhanced if emission from the system were inhibited unless skin was the target.
In the future, devices similar to the above products may be developed that are intended for use by untrained users and offered for sale directly to consumers. Not only will such products benefit from the integration of a sensor that can restrict emission to only those times in which the device output is targeted to skin, the incorporation of a sensor may prove critical to the safe use of such devices. Just as with the FDA restricted systems described above, hazards posed by inadvertent emission from these direct-sale to the consumer products include thermal damage to the eye that may cause blindness, ignition of upholstery or clothing, or in the case of devices that could treat acne with blue or near ultraviolet (U.V.) radiation, unwanted chemical damage to the eyes. Sensors that permit untrained operators to use radiation emitting devices safely on their skin may be the enabling technology for home-use self-treatment with laser and intense light dermatological devices.
However, products that are sold directly to consumers for in-home self treatment must be inexpensive, reliable, and small, and uncomplicated to use. Therefore, any diagnostic system incorporated into a device intended for the consumer market is also preferably inexpensive, reliable, and small, and simple.
It should be noted that devices that merely sense and require contact with a surface prior to emission do increase the safety of these types of systems. However, a mere contact sensor can be easily fooled by surfaces other than skin. Therefore, a system that uses a sensor that can discriminate between skin and other surfaces in conjunction with a contact sensor, would be much more reliable in detecting surfaces that are not skin.